5 



MANGANESE 

IN THE 

FOUNDRY 




Published by 

KENDALL & FLICK 

Washington. D. C. 



Printed by 

BYRON S. ADAMS 

Washington, D. C. 



MANGANESE 



IN THE 



FOUNDRY 



A DESCRIPTION OF ITS METALLURGICAL CHAR- 
ACTER, INFLUENCES AND VALUE IN CAST-IRON, 
WITH DIRECTIONS FOR USE. 






i t -i » . ii > » 



By J. E. CARTWRIGHT 



1903 
Kendau & Fuck 

WASHINGTON, D. C. 




THE LIBRARY OF 
CONGRESS, 

Two Copies Received 

MAY 28 1903 

Copyright Entry 

CLASS CL XXc. No. 

COPY B. 



Copyrighted 1898 
By W. P. ROBERTSON. 

* Copyrighted 1903 
By W. P. ROBERTSON. 
Revised Edition 





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3-WVf 9,0 



PART I. 



The increasing use of manganese in foundry 
practice and the frequent discussions in foundry 
associations have given the impression that a mono- 
graph on the subject, relating briefly a history of 
the metal manganese, its progress in industrial uses, 
metallurgical characteristics, and methods of using 
it for different classes of foundry work, might prove 
of some value to those engaged in operating iron 
foundries. The following pages are largely a com- 
pilation of statements from the works of leading 
writers on metallurgy, Howe, Roberts- Austin, 
Turner, Hiorns and others. 

Probably no better introduction to the subject 
can be found than the words of Deshayes in his 
paper on the 

Position of Manganese in Modern Industry. 

" No body among the metals and the metalloids 
(titanium, tungsten, chromium, phosphorus, etc.,) 
has occupied a more prominent position in modern 
metallurgy than manganese, and it is chiefly due 
to its great affinity for oxygen. When this sub- 
stance was discovered in 1774 by Gahn, no one 
would have thought that the new element, so deli- 
cate by itself, without any direct industrial use, 
would become, in the middle of the Nineteenth 
Century, one of the most powerful and necessary 
instruments for the success of the Bessemer process, 

Published by Kendall & Flick, Washington, D. C. 



as well for its deoxidizing properties as for the quali- 
ties which it imparts to steel, increasing its resist- 
ance, its 'durability and its elasticity. * * * 
Without entering into a complete history (which 
is beyond the task here assumed), it will not be 
without interest to recall how, when manganese 
was first obtained in a pure state, it was supposed 
that it would remain simply an object of curiosity 
in the laboratory ; but when its presence was proved 
in Spiegeleisen and when it came to be considered 
an essential ingredient, in the best German and 
English works, for cutlery steel, then we find its 
qualities become better and better appreciated." — 
[M. V. Deshayes, Bull. Soc. Chim. Paris, XXXVI ; page 184.] 

Manganese. 

Symbol, Mn. Atomic Wt. 55. Specific Grav., 8. 
Manganese belongs to the iron group of metals. It 
is a grayish white metal, never occurring native. 
The pure metal is obtained by reduction of i:s 
oxide. It oxidizes rapidly in the air, and decom- 
poses water slowly at the ordinary temperature. It 
alloys readily with iron, steel and copper, and its 
chief use is in the formation of such alloys. It 
alloys with iron in all ratios. It is not used in the 
unalloyed state. In one or the other of its various 
forms manganese is widely distributed in nature ; 
one of the most common is pyrolusite (manganese 
dioxide or peroxide), Mn 2 ., and this is the most 
valuable of its ores. Manganese forms two basic, 
two indifferent, and two acid oxides. The oxides 
of manganese and many of its salts find extended 
application in the arts. 

Ferro=Manganese. " This may be consisted a 
variety of pig iron in which the iron is r^paCed 
largely by manganese. It is produced by smelt- 

PUBLISHED BY KENDALL & FLICK, WASHINGTON^ D. C. 



ing in a blast furnace from ores rich in oxide of 
manganese, and it is possible to obtain a product 
having as much as 87% of manganese. When this 
metal contains about 20% manganese its fracture 
shows large crystalline cleavage, and is termed 
spiegeleisen. The variety known as ferro-man- 
ganese is a hard crystalline metal, but the frac- 
tured surface does not present the large cleavage 
planes characteristic of spiegel." — [Hiorns.] 

The authorities are not agreed as to the line di- 
viding spiegeleisen and ferro-manganese. Some 
class as spiegel all pig iron containing 5% to 20 a / 
manganese ; and ferro-manganese all such metal 
containing a higher percentage of manganese than 
io c /c. Others use 40% manganese as the dividing 
line, all below that percentage being spiegel, and 
all above it, ferrc-manganese. The usual market 
grade of ferro-manganese now sold contains 80^ 
manganese. 

Carbon and Manganese in Iron. Any study of 
the action and influences of manganese in iron or 
steel must necessarily be made in connection with 
carbon, having in view the carbon contents and 
the influence of the manganese and carbon upon 
each other, and of both elements jointly and sepa- 
rately upon iron. 

" It may be doubted whether the exact influence 
(on iron) exercised by varying proportions of 
carbon has been accurately determined. A dis- 
tinguished authority (Mr. H. M. Howe) thinks 
that it is not yet known. He points out that he 
has plotted in a single curve the results of over 
2,500 tests, and yet the conclusion he arrives at is 
that we are not at present able to quantitatively 
express the effect of carbon. The fact is that 

Published by Kendall & Flick, Washington, D. C. 



metallurgists are only beginning to realize that 
the effect of elements in the presence of each 
other is very complicated, and that it is absolutely 
necessary to study the effect of any given element 
on an absolutely pure mass of the metal to be 
tested. ' ' — [Roberts-Austin.] 

Total Carbon, or Saturation Point for Car= 
bon. " The quantity of carbon with which molten 
iron can combine (=conibined + graphitic carbon 
of the solidified iron ) depends chiefly on the per- 
centage of silicon, sulphur and manganese which 
it contains. The former two elements lower the 
saturation point for carbon, while manganese 
raises it. Chemically pure iron can apparently only 
combine with about 4.63% of carbon." — [Howe.] 

It will be found, therefore, that irons high in 
manganese are also high in combined carbon, 
unless a high percentage of silicon is present at 
the same time, in which case the tendency of the 
manganese to raise the percentage of carbon may 
be counteracted by the influence of the silicon to 
lower it. Ferro-manganese often contains about 
5.5% carbon and occasionally 7%. With increas- 
ing manganese the saturation point for carbon 
rises as follows : 

Manganese 10 to 20.$ I 35.$ I 50.$ I 65.$ I 80. j> 

Corresponding Saturation 5.^ | 5.5^ | 6.$ | 6.5$ | 7.$ 

points for carbon. 

Volatility of Manganese. Manganese appears 
to volatilize with considerable rapidity at a white 
heat. Thus, Jordan states that at a French blast- 
furnace 10% of the manganese charged could not 
be accounted for by the contents of metal, slag 
and dust. Further, ferro-manganese of 84.9% 
manganese lost 4% of its manganese on being ex- 

PUBLISHED BY KENDALL & FLICK, WASHINGTON, D. C. 



posed to the heat of a wind-furnace for i]/ z hours 
in a brasqued crucible. 

"If an iron containing manganese is remelted 
more or less of the maganese will escape by vol- 
atilization, and by oxidation with the other ele- 
ments in the iron."— [Keep.] 

Fusibility. The fusion point of manganese is 
1,900° C. 

Desulphurization by Manganese. "The de- 
sulphurizing effect of manganese is much more 
marked than that of silicon. With iron such as 
is used for the basic process the silicon is low 
(usually 1.% or less) and sulphur would therefore 
be present in relatively large quantities if man- 
ganese were not added to the charge in sufficient 
quantity to give some 1.5$ of manganese in the 
metal. — [Turner.] 

Turner also says: "Manganese leads to the 

much more perfect removal of sulphur, which is 

eliminated in the form of manganous sulphide 

(Mn S.) ; this floats to the surface of the molten 

iron and forms part of the slag which collects at 

the top of the metal. This fact, which has been 

long observed, forms the basis of the process of 

sulphur elimination recently patented by Massenez, 

in wh ; ch manganese is added to molten iron rich 

in sulphur (as high as 2% or 3% sulphur), 

which is thus purified and rendered suitable for 

the use of steel makers." 

(For description of Massenez process of desulphurization of 
pig iron, see Sci. Amer. Sup. No. 829.) 

Walrand, after melting sulphurous cast-iron in 
one crucible and manganese under lime in another, 
poured the cast-iron into the manganese and 
stirred the mixture for a minute, when an insup- 

PtTBLISHED BY KENDALL & FLICK, \WASHINGTON, D. C 



8 

portable odor of sulphurous acid arose from the 
supernatant slag ; the sulphur in the cast-iron fell 
from 0.50 to 0.06% . 

Sulphur and manganese probably combined, 
and rose to the surface, when, exposed to the air, 
the sulphur became rapidly oxidized. — [Howe.] 

Akerman considers that manganese drags sul- 
phur into the blast-furnace slag even more power- 
fully than calcium does. 

In three sets of experiments (1) on phosphoric, 
(2) on sulphurous, (3) on siliceous cast-iron re- 
spectively, each melted, (A) alone, and (B) with 
metallic manganese, Caron found that the addi- 
tion of manganese energetically expelled sulphur, 
increased the percentage of silicon (by reducing 
it from the walls of the cupola), but had little 
effect on phosphorous. 

" If sulphur be present, some of the manganese 
will be likely to unite with it and escape, thus re- 
ducing the amount of both elements in the cast- 
ing. Hence, in remelting irons, some of the sul- 
phur which has entered from the fuel with which 
the iron is melted will very likely unite with some 
of the manganese in the irons which makes up the 
mixture and escape." — [Keep, Vol. 20, page 291, Trans. 
Amer, I. M. E.] 

"Regarding sulphur; during my experiments 
whenever I have put ferro-manganese into the 
ladle from our cupola sulphur became apparent to 
the smell, which I presume indicatesthat the man- 
ganese eliminates the sulphur. It seems to me, 
moreover, that in Mr. Howe's work on steel this 
is so conclusively proved as to make further ex- 
periment unnecessary. — [ibid, page 314.— Discussion.] 

Published by Kendall & Flick, Washington, D. C. 



9 

Order of Oxidation. " Next to silicon, mangan- 
ese is the most easily oxidizable element in pig- 
iron. Manganese, therefore, protects the iron 
from oxidation until it is itself completely oxid- 
ized." — [Wedding.] 

Occlusion of Gases. '* Metals when melted in 
contact with air or other gases, absorb them more 
or less, and retain a portion after solidification ; the 
portion thus retained is said to be occluded." 

— [Hiorns.l 

" It is well know that at the conclusion of the 
Bessemer process oxygen from the air blown 
through the metal becomes intimately associated 
with the iron ; but the manner in which the oxy- 
gen is held, whether as oxide, or as dissolved gas, 
appears to be still obscure. One thing is certain, 
that the oxygen may be readily removed from the 
iron by the action of manganese." — [Roberts-Austin.] 

What are known as "blowholes" and other 
unsound spots in cast-iron and steel are caused 
by occluded gases. 

" Be it by increasing the solubility of gases, or 
by preventing the oxidation of carbon and the 
formation of carbonic oxide, manganese hinders 
the formation of ' blowholes.' "—[Howe.] 

Effects of Different Percentages of flangan- 
ese. Manganese, in its action in alloys of iron, 
is probably the most remarkable of the elements 
usually found in pig and cast-iron and steel. 

(a.) Mr. A. E. Outerbridge, in a lecture, de- 
livered before the Franklin Institute in 1888, said: 
"A remarkable effect is produced upon the charac- 
ter of hard iron by adding to the molten metal, 

Published by Kendall & Flick, Washington, D. C. 



10 

a moment before pouring it into a mould, a very 
small quantity of powdered ferro-manganese, say 
i pound of ferro-manganese in 600 pounds of 
iron, and thoroughly diffusing it through the mol- 
ten mass by stirring with an iron rod. The result 
of several hundred carefully conducted experi- 
ments which I have made enables me to say that 
the transverse strength of the metal is increased 
30 to 40 fo, the shrinkage is decreased 20 to 30% 
and the depth of chill is decreased about 25%, 
while nearly one-half of the combined carbon is 
changed into free carbon ; the percentage of man- 
ganese in the iron is not sensibly increased by this 
dose, the small proportion of manganese which 
was added being found in the form of oxide in the 
scoria." The points in this statement to be par- 
ticularly noted are, 1st, that Mr. Outerbridge was 
experimenting with hard or chilling irons, which 
probably contained less than 2% silicon and in 
which the carbon was doubtless largely in the 
combined form ; and, 2nd, the very small quantity 
of manganese added to the iron to cause such 
striking effects. The quantity of ferro-manganese 
was but 0.166% of the weight of iron ; and, as it 
was doubtless 80% ferro-manganese, the actual 
addition of metallic manganese was but 0.133%. 

Mr. Outerbridge does not speak of any exami- 
nation, in these experiments, in regard to sulphur. 
But as the desulphurizing power of manganese is 
now well established, there can be little doubt 
that the remarkable effects he obtained were in 
some degree due to the desulphurizing action of 
the manganese and not wholly to its effect of 
forcing combined carbon over to the graphitic 
state. 

Published by Kendall & Flick, Washington, D. C. 



11 

(b. ) While we have no recorded tests of cast- 
iron containing 3, 4 or 5% or more manganese, 
by analogy any experiments along that line should 
show castings of a hard and brittle character. 
Spiegeleisen is pig-iron (cast-iron) containing 5% 
to 20% manganese, and is hard, brittle and crys- 
talline. Steel containing 4% to 5% manganese is 
hard, brittle and of little strength. Hadfield men- 
tions cast bars of steel 2)4 inches square, 30 
inches long, containing about 0.48% carbon and 
4.9% manganese, which were so fragile that when 
dropped on a paved floor from a height of three 
or four feet, broke into several pieces. In tests 
for transverse strength such bars broke under a 
load of 3^ tons, while similar bars of ordinary 
cast-iron stood a breaking load of 12 tons. Of 
such steel containing 4% to 5% manganese, he 
says: " No cohesion seemed to exist between the 
particles." 

(c.) Passing to alloys of iron with higher per- 
centages of manganese, we are brought to con- 
sider one of the most remarkable discoveries of 
recent years in metallurgy, namely, Hadfield's 
manganese steel. Hadfield found that when to 
decarburized iron was added 7% to 20% mangan- 
ese the result was a new and, in many respects, 
a wonderful metal, combining great strength, 
toughness and hardness. A bar of this metal 
similar to those described {2% inches square, by 
30 inches long) stood breaking loads high as 38 
tons, while tensile tests of 140,000 lbs. per square 
inch have been obtained. Unlike carbon steels, 
which are hardened (tampered) by heating and 
plunging into water, this metal, paradoxica ly, is 
somewhat softened and decidedly toughened by 

Published by Kendall & Flick, Washington, D. C. 



12 

heating and then rapidly cooling in water. An- 
other peculiarity of this metal is that it is almost 
completely non-magnetic. A study of this remark- 
able metal is interesting, and for a full description 
of it reference is made to the proceedings of the 
Inst, of Civil Engineers, 1888. The most striking 
and useful results were obtained with the metal 
containing about 14% or 15% manganese. 

This effect of manganese in percentages from 
j% to 30$, as shown in Hadfield's steel, does not 
extend to cast-iron, for with these percentages of 
manganese in cast-iron we have spiegeleisen as the 
result. 

What has beeu said under the heads (a,) (b,) 
and (c) is sufficient to illustrate the very different 
effects of various percentages of manganese in 
iron. The alloys of manganese with copper are 
interesting as well as very valuable in modern in- 
dustry. Works on metallurgy describe these use- 
ful alloys, and there is also an interesting paper 
in Engineering, May 27, 1881, by Deshayes on 
these manganese bronzes. 



Published by Kendall & Flick, Washington, P. C. 



13 



PART II. 

Manganese in Foundry Practice. 

u We still wonder at the minuteness of the 
quantity of certain elements which can pro- 
foundly affect the properties of metals." — [Roberts- 
Austin.] 

Again the same celebrated metallurgist says, " It 
is difficult to describe briefly the effect of small 
quantities of manganese on the mechanical prop- 
erties of carburized iron." 

Manganese as used in steel and iron processes is 
generally in the form of spiegeleisen(2o% metallic 
mang. ) or ferro-manganese (80% metallic mang. ) 
and in foundry practice the latter is generally used. 

In considering the uses of manganese in iron 
foundries the subject may be divided under two 
heads, according to the purpose for which it is 
used, — first, softening hard irons, and, second, 
strengthening soft irons. 

1st. The use of very small quantities of ferro- 
manganese for the softening, strengthening and 
purifying effects on hard or chilling irons. What 
has already been said of Outerbridge's experiments 
(page 10) is applicable here. Referring to these 
experiments, Turner says : (Metal, of Iron and 
Steel, 1895, p. 205.) " These observations accord 
with those made at Smethwick by the author, 
though in all probability their success depends on 
the peculiar composition of the cast-iron used." 
Again, the same authority observes : " From the 
examination of the tests conducted at Woolwich 

Published by Kendall &, Flick, Washington, D. C. 



14 

in 1858, and numerous analyses of selected sam- 
ples of cast-iron of special strength, the author 
concluded that the presence of some manganese 
was rather beneficial than otherwise in foundry 
practice, though probably any benefit ceases when 
the proportion of manganese is much greater than 
1%. * * * Cases have come under the author's 
notice in which in actual practice ferro-manganese 
has been added in small quantity to molten metal 
in a foundry ladle, with the result that the iron 
has been very much softened and improved. The 
reason for this doubtless lies in the fact that man- 
ganese counteracts the effect of sulphur and silicon, 
tending to eliminate the former and neutralize the 
latter, and so, where common iron is employed, it 
sometimes happens that ferro-manganese may be 
used as a softener." 

However, since Outerbridge made known the 
results of his experiments, and since Turner made 
the observations he mentions, the car wheel foun- 
dries during the last ten years have generally 
adopted the use of ferro-manganese and established 
the fact of beneficial results from its use in the 
class of work they make. The powerful action of a 
small quantity of finely ground or powdered ferro- 
manganese added in the ladle to chilling irons 
has gradually become known to them during the 
last ten years, and one after another they have 
adopted its use, and the fact that, when once 
adopted, they never change to their old practice, 
is good evidence that it yields results that are sat- 
isfactory. It enables the remelting of a very 
large proportion of old car wheels and similar 
scrap, and the use of grades of pig iron which 
formerly were not considered suitable for this class 
of castings. That there has been no deterioration, 
Published by Kendall & Flick, Washington, D. C. 



15 

but, instead, a great improvement in the quality of 
car wheels made b)' the method now used is shown 
by the fact that the severity of tests prescribed by 
railroads, and the guaranteed life or mileage of 
wheels have been raised repeatedly during the 
last ten years ; and yet the car wheel makers have 
kept pace with these severer requirements,and have 
no trouble in making wheels by this modern 
method that easily meet these higher tests and 
guarantees. 

The method followed by car wheel foundries is 
practically that described by Mr. Outerbridge, — 
the placing of a very small quantity of ground 
ferro-manganese in the ladle just before pouring, 
except that it is now customary to throw the ferro- 
manganese in the bottom of the ladle just as the 
iron is about to run into it. By this means the 
diffusion is immediate and complete, and there is 
no necessity to stir the metal. The usual practice 
is to put i^ to 2 lbs. of the ferro-manganese 
powder in a ladle holding enough iron to pour a 
600 or 650 lbs. wheel, the quantity and methods 
varying slightly with different foundries, appar- 
ently depending somewhat on their individual 
ideas, and the kinds of iron used to make up the 
wheel mixture. It is probable that 2 lbs. of 
ground ferro-manganese is sufficient in any mix- 
ture, for the largest car wheels, and possible that 
even a smaller percentage would prove equally 
effective. The real point sought in this case is 
not an increase in the manganese content of the 
casting, but it is the softening (chill-reducing), 
strengthening, sulphur-cleansing and reheating 
effects of the small dose of ferro-manganese upon 
the molten iron. It will be observed the quantity 

Published by Kendall & Flick, Washington, D. C. 



16 

of ferro-manganese used in the Outerbridge ex- 
periments was o.i 66% and even where 2 lbs. is 
used for a 600 lbs. wheel the percentage is but 
0.33, and as the ferro-manganese is Sofo metallic 
manganese the percentage of manganese really 
added in the ladle in these cases would be 0.133 
and 0.267. How much of this manganese remains 
in the iron, and how much escapes in the scoria or 
dross as oxide or sulphide of manganese ? As far 
as known no determinations along this line have 
been made, but from the known tendency of man- 
ganese to oxidize, to unite with sulphur, and pos- 
sibly to volatilize, it is fairly inferable that a very 
considerable portion of the manganese placed in 
the ladle is utilized in this purifying process and 
passes away in the scoria or gases. 

Another advantage of using mangauese in this 
manner which is worth considering is that, for 
chilled castings, it puts the regulation of the depth 
of chill under control after the iron is melted and 
ready for pouring. Enough of the molten iron can 
be taken in a small ladle to pour one or more chill 
test blocks. These are quickly cooled and broken, 
and show if the chill has been sufficiently reduced, 
if not, the charge of ferro-manganese powder is to 
be very slightly increased ; if, on the other hand, the 
chill does not show depth enough, the charge of 
manganese must be slightly reduced. These tests 
can be made so quickly that there is no interrup- 
tion to the operation of pouring. 

Some years ago Mr. Wm. Wilmington patented a 
process for softening the hubs and plates of car 
wheels without affecting the chilled tread, by 
sprinkling powdered ferro-manganese into the 
head box after the mould is partly filled. It has 

Published by Kendall & Flick, Washington, D. C. 



17 

been claimed that new wheels were made in this 
manner entirely out of old wheels, without the 
use of pig iron. The error in the theory of this 
method is that it supposes that if the very small 
quantity of manganese used entered the iron 
which forms the chilled tread of the wheel it 
would in some way have a deleterious effect on 
the quality of the chill or increase its depth. That 
such effects do not follow where the manganese is 
added in the ladle and consequently is diffused 
through the entire mass of iron which makes the 
wheel has been demonstrated by Mr. Outerbridge's 
experiments and by the fact that the latter method 
has been adopted by wheel makers almost univer- 
sally. Mr. Wilmington's method misses two im- 
portant points — first, that the very purpose of 
using manganese in a mixture that would other- 
wise give too great depth of chill is, in a degree, 
to soften, toughen, and purify it, and the chill or 
tread of the wheel needs these effects as much as, 
if not more, than the iron which goes to form the 
hub and plate ; and, second, that of the very small 
quantity of manganese used some escapes, and 
even if it all remained in the iron as manganese 
content it is not sufficient to affect the chill or tread 
in the way he evidently figured it would. Wil- 
mington's method would be a good one to follow 
where the iron mixture is just right to give correct 
depth of chill and it is desired to soften and 
toughen the plate and hub of wheels. 

It should be constantly borne in mind that the 
method described on pages 15 and 16 is to be ap- 
plied to mixtures of iron which, chilled, will have 
a greater depth of chill than desired, unless 
treated with manganese ; in other words, it is ap- 

PUBLISHED BY KENDALL & FLICK, WASHINGTON, D. C. 



18 

plicable to irons so hard and chilling in character 
that they require some softening. 

It may not be out of place here to speak briefly 
of the influence of varying quantities of metals on 
each other, to show the decided effect of small 
quantities of one element on large masses of another 
element. Lord Kelvin has shown how very im- 
portant the purity of copper is, and how remark- 
able is the action of the impurity. The presence 
of o.i % of bismuth in the copper would, by reduc- 
ing its conductivity, be fatal to the commercial 
success of the ocean cables. The addition to gold 
of 0.2% by weight of bismuth would, for coinage, 
convert the gold into a useless material, which 
would crumble under the pressure exerted through 
the die. Sir Hussey Vivian says that joVo P art °f 
antimony will convert the best selected copper 
into the worst conceivable. Instances of similar 
nature might be multiplied indefinitely, and no- 
where are they more striking than in the effects 
of exceedingly small percentages of some ele- 
ments upon iron. 

2d. The usefulness of manganese in foundries 
making grey iron castings, where the mixture of 
irons used is generally soft enough, is probably 
not as yet so clearly established. There is a lack 
of recorded tests along this line. The mixtures of 
iron used in such foundries, whether the output 
is heavy or light machinery, stove plate, or. some 
other class of grey castings, usually contains 2. to 
3.% silicon, 3. to 3.5% carbon (of which the larger 
part is graphitic,) and more or less phosphorus, 
manganese and sulphur. The opportunity man- 
ganese has in such mixtures to show beneficial re- 
sults is to increase the tensile and transverse 

Published by Kendall & Flick, Washington, D. C. 



19 

strengths, to partially eliminate sulphur and ren- 
der the castings less liable to blowholes, by aiding 
the escape of gases. If there is already present in 
the mixture i% of manganese any small addition 
which could be made without risking a hardening 
effect would be of doubtful value. 

In a series of tests by Mr. W.J. Keep ("The 
Foundry," Jan., 1898,) for the effects of aluminum 
and manganese, used separately and together, he 
used mixtures of irons which, from the analysis of 
the test bars, ran about as follows : 

Silicon 1.60 to 2.25$ (Est. loss in melting.) 

Manganese 0.50100.75$ " " " •' 

Phosphorus 0.65 to 1.21^ 

Graph. Carb. about 3.00$ 

Comb. " " 0.35$ 

Sulphur o 01 to 0.023 (except one series, 0.05$) 

No statement is made as to the general character 
of the castings these mixtures made when un- 
treated by manganese — as to whether they were of 
average strength, softness, etc. It may be judged, 
however, from the fair amount of silicon contained, 
the phosphorus, manganese and free carbon being 
fully up to the average, if not above it, and the 
unusually low sulphur, that the experimenter was 
working with good material, which should have 
made what are generally regarded as good strong, 
soft castings. As the irons used were unusually 
low in sulphur there was little room for the added 
manganese to show one of its best effects — desul- 
phurization. It should be noted also that the irons 
were already above the average of foundry irons 
in manganese contents ; and considering the sili- 
con, phosphorus and free carbon present it would 
seem that, on the score of softness and fluidity, 
the irons needed no treatment. The net result of 
this series of tests, so far as the influence of the 

Published by Kendall & Flick, Washington, D. C. 



20 

additions of manganese is concerned, was an in- 
crease of tensile strength of about 9%, and of 
transverse strength of about nj^%. Mr. Keep 
does not mention any bad effects from thus in- 
creasing the manganese. The analyses of the sev- 
eral tests show increases of manganese contents 
varying from 0.310 to 1. 111%, indicating additions 
of ferro-manganese in the ladle, we should judge, 
ranging from 0.50 to 1.50%. He remarks, " In the 
metal to which the ferro-manganese was added no 
blowholes were seen, nor any sign of excessive 
chill, although the shrinkage was slightly aug- 
mented." And again, "In every case but one 
(Series II) the addition of ferro-manganese in- 
creased the transverse strength without decreasing 
the deflection." In the last test (Series V) the 
untreated bars analyzed 0.55% manganese, and the 
treated bars ( ferro-mang. added) analyzed 1.661%. 
This is an increase of i.m fo in manganese con- 
tent, to obtain which it was probably necessary to 
add about 1.50% ferro-mang. in the ladle — possi- 
bly more. The bars from the regular mixture gave 
average tensile strength of 20,500 lbs. and trans- 
verse breaking strength of 1,965 lbs. The man- 
ganesed bars gave average 24,750 lbs. tensile, and 
2,462 lbs. transverse strength. Here is an increase 
of 19% in the tensile, and 25^ in the transverse 
strength. It should be further noted, that, while 
all these bars were cast to be 1 inch square, in the 
above test the exact measurements showed the 
manganesed bars to be smaller than the untreated 
bars, — which difference in size leaves something 
further in comparative strength to be credited to 
the manganesed bars. 

As showing that the addition of manganese to 
Published by Kendall & Flick, Washington, D. C. 



21 

ordinary foundry mixtures will increase strength 
the following is quoted from ai article by Mr. S. 
S. Knight in " The Foundry," Nov., 1897. " While 
using high manganese irons we found that our test 
bars made from these mixtures invariably broke 
higher than a corresponding mixture of low man- 
ganese metal. Scores of analyses were made to 
prove the cause of this phenomenon, and in every 
case high manganese was shown with no other 
phenomenal feature. Low manganese irons were 
tried having enough ferro-manganese added in the 
ladle to place the contents of this element over 1 % . 
The results were the same as if originally high 
manganese iron had been used. The two test bars 
given below will show for themselves the advan- 
tage of gain ia ultimate strength to be made in this 
manner. Both bars v ere cast on end and broken 
36 inches between supports on a Riehle machine, 
having the load applied at the center with a uni- 
form acceleration. 

1st Bar. 2nd Bar. 

Breaking strain 928 lbs. 736 Its. 

Deflection 088 inch. 0.97 inch. 

Shrinkage, in one foot 0.13 inch. 12 inch. 

Size of bar .97i"x.95o // .988" x .990". 

The first bar had a small amount of ferro-man- 
gauese added in the ladle, the iron being held until 
it flashed strongly before pouring. The analysis 
of the first bar was : 

Silicon 1.98056. 

Phosphorus -558$. 

Sulphur .050$. 

Manganese 1.002$. 

The analysis of the second bar was practically 
the same as the first bar, except in manganese, 
which was .712%." It will be noted that the sec- 
ond bar was larger than the first, although both 
were evidently cast to be one inch square. The 

Published by Kendall & Flick, Washington, D. C. 



22 

increase of transverse strength shown in this case 
by the addition of a small quantity of ferro-man- 
ganese is 26%. 

Some further examples along this line could be 
adduced to show that if, to an ordinary grey iron 
foundry mixture is added enough ferro-manganese 
to raise the manganese content to 1.% there is a 
decided gain in transverse and tensile strengths, 
and that up to this point the manganese manifests 
no undesirable effects. If the manganese is raised 
beyond 1.5% a distinct hardening effect will 
set in. 

The quantity of Ferro=Manganese to use, 
and method of using. The most effective and 
economical way of adding manganese to cast-iron 
is to place powdered ferro-manganese on the bot- 
tom of the ladle and run the iron on it. The addi- 
tion of lump ferro-manganese in the cupo^ has 
been found to be less effective, and not economical 
in ultimate results. When melted in the cupola 
the manganese is subjected to greater opportuni- 
ties for loss and waste, through oxidation and vola- 
tility. The oxidation, to a certain extent, is de- 
sired and beneficial, but beyond that is wasteful. 
To the extent that it is beueficial it is obtained by 
adding in the ladle. Howe states that oxide of 
manganese gives slags so strongly corrosive that 
their effect on the linings of open-hearth, cupola 
and other melting furnaces must be guarded 
against. 

/// hard or chilling irons, to soften, to regulate, or 
reduce chill, or prevent increase of chill on remelt, 
— several expressions of the same influence — the 
practice already described as Outerbridge's or the 
car wheel foundry method has proven to be the 

Published by Kendall & Flick, Washington, D. C. 



23 

best. Probably the best starting point is I lb. 
of ground ferro-rnanganese to about 300 lbs. of 
iron. If this does not produce the exact effect 
wished, the dose may be very slightly increased 
or decreased, according as it is desired to increase 
or lessen the softening effect. It may prove that a 
proportion of 1 lb. of ferro-manganese to 400 
lbs. iron will yield the best result, considering the 
character of the work in hand and the irons form- 
ing the mixture, or again 1 lb. to 250 lbs. may 
give belter results. Where the mixture is of 
chilling irons, either pig, old car wheels or other 
scrap of that character, the manganese is used to 
modify the chilling tendency of snch irons, and 
at the same time to otherwise improve the iron. It 
is best to use the ferro-manganese in the shape of 
a uniform powder, of about the grain of sand. 
If it is finer the heated air rising from the ladle 
carries some of it away in dust ; if it is too coarse 
there is not the requisite instantaneous diffu- 
sion and reduction by the molten metal. The 
nearer instantaneous is the diffusion and reaction 
in the ladle the more effective it is — and, to a 
certain extent, the less the quantity required to 
produce a given effect. 

In grey iron foundry mixtures* where mangan- 
ese is added primarily to stengthen and inci- 
dentally to prevent blowholes and otherwise im- 
prove the iron, about 1 lb. of the ground ferro- 
manganese to 200 lbs. of iron will usually be ap- 
proximately the proper proportion. Something 
depends upon the manganese contents of the mix- 
ture before treatment. If the manganese content 
of the iron to be treated is known add enough 
ferro-manganese in the ladle to raise the percent- 

Phblished by Kendall & Flick, Washington, D. C. 



24 

age of that element in the casting to i.%. If the 
castings are of a class that some degree of soft- 
ness can be spared to secure greater strength the 
percentage of manganese may be raised to 1.25% 
In calculating the weight of the dose of ferro- 
manganese to be added bear in mind it is 80% or 
four-fifths metallic manganese. It must also be 
figured that there is some loss of the manganese 
as part of the beneficial action which takes place 
in the ladle, by oxidation and escaping gas. 
What the extent of this disappearance of the 
manganese will be in any case would be difficult 
to state. It may safely be figured at one-fourth or 
more of the quantity charged. 

In other words, where the object is to strengthen 
soft grey iron, manganese may be added to the ex- 
tent of about i c /c, or 1 lb. manganese to 100 lbs. 
iron. 

If, however, the object is to soften grey iron 
which would otherwise produce hard castings, and, 
incidentally, to somewhat strengthen and gen- 
erally improve the castings, the dose of manganese 
must be kept small — say 1 lb. manganese to 300 
lbs. of iron. 

The results of this inquiry into the character, 
influences and value of manganese in iron castings 
may be briefly summed up as follows : 

1. Used in very small proportion it acts to soften 
chilling irons or hard iron. 

2. Used in somewhat larger proportion, say ifc, 
it acts to strengthen soft irons. 

3. It aids the escape of gases, thus reducing the 
chance of blowholes or unsound castings. 

4. It acts strongly to eliminate sulphur. 

5. In the case of chilled castings, car wheels, 
etc., it puts the regulation of depth of chill under 
control, after the iron is melted and ready to pour. 

6. Whether it is hard iron or soft iron that is 
treated with an addition of manganese there is a 
general improvement of the iron, in solidity, 
toughness, etc. 

There will doubtless be some first failures to 
secure desired results, but experience will show 
that manganese is a valuable adjunct in foundry 
practice for nearly all classes of castings. 

Published by Kendall & Flick, Washington, D. C. 



MAY 28 1903 



Published by 



KENDALL & FLICK 

MANGANESE 

WASHINGTON, D.C. 



